COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Cessna 188 (Agwagon) Series Aeroplanes AD/CESSNA 188/25 Amdt 1 Engine Air Inlet Duct 6/75 Applicability: All model A188 and A188B with S/Nos. 18800833 to 18801824 including those S/Nos. with a suffix "T". Requirement: Action in accordance with either Cessna SL SE75-5 or SL SE74-23. Note: FAA AD's 74-23-07 and 75-09-06 refer. Compliance: Within 50 hours time in service after 12 May 1975.